Merging several JSON files in TypeScript - json

Question

I am currently tasked with finding the amount of times a specific email has contacted us. The contacts are stored in JSON files and the key should be "email".
The thing is there are potentially infinite JSON files so I would like to merge them in to a single object and iterate to count the email frequency.
So to be clear I need to read in the JSON content. Produce it as a log
consume the message
transform that message into a tally of logs per email used.
My thought process may be wrong but I am thinking I need to merge all JSON files into a single object that I can then iterate over and manipulate if needed. However I believe I am having issues with the synchronicity of it.
I am using fs to read in (I think in this case 100 JSON files) running a forEach and attempting to push each into an array but the array comes back empty. I am sure I am missing something simple but upon reading the documentation for fs I think I just may be missing it.
const fs = require('fs');
let consumed = [];
const fConsume = () => {
fs.readdir(testFolder, (err, files) => {
files.forEach(file => {
let rawData = fs.readFileSync(`${testFolder}/${file}`);
let readable = JSON.parse(rawData);
consumed.push(readable);
});
})
}
fConsume();
console.log(consumed);
For reference this is what each JSON object looks like, and there are several per imported file.
{
id: 'a7294140-a453-4f3c-91b6-210819e2c43e',
email: 'ethan.hernandez#microsoft.com',
message: 'successfully handled skipped operation.'
},

Answer 1

fs.readdir() is async, so your function returns before it executes the callback. If you want to use synchronous code here, you need to use fs.readdirSync() instead:
const fs = require('fs');
let consumed = [];
const fConsume = () => {
const files = fs.readdirSync(testFolder)
files.forEach(file => {
let rawData = fs.readFileSync(`${testFolder}/${file}`);
let readable = JSON.parse(rawData);
consumed.push(readable);
});
}
fConsume();
console.log(consumed);